Fuel injector and method of making same



June 20, 1967 M. J. BERLYN 3,326,191

I MARTIN J. BE? LYN BY W A TOE/VEY June 20, 1967 M. J. BERLYN 3,326,191

FUEL INJECTOR AND METHOD OF MAKING SAME Filed July 6, 1964 2 Sheets-Sheet 2 30 I 2s \v g g S W 'INVENTOR.

MARTIN J. BEFELYN BY I v iT;OPA/E K United States Patent 3,326,191 FUEL INJECTOR AND METHOD OF MAKING SAME Martin J Berlyn, Morley, Leeds, England, assignor to Hailwood & Ackroyd, Limited, Leeds, England Filed July 6, 1964, Ser. No. 380,270 3 Claims. (Cl. 123-32) This invention relates to fuel injection nozzles and has particular reference to a new and improved nozzle adapted to be installed in an engine cylinder with the axis of the nozzle holder inclined at an angle to the axis of the engine cylinder.

An object of the invention is to provide a nozzle of the type set forth wherein the performance of all of the nozzle orifices is identical even though the nozzle holder is inclined relative to the engine cylinder.

Another object is to provide a new and improved method of making a nozzle of the type set forth.

In an internal combustion engine of the type having direct fuel injection into the cylinder, and having valves in the cylinder head, it is sometimes impossible for the designer to reconcile space requirements of the valving with the preferred arrangement of the injection nozzle holder, whereby the nozzle holder should be installed coaxial, or parallel, with the axis of the engine cylinder.

In many cases, the designer has compromised by arranging the nozzle holder with its axis inclined at an angle to the axis of the cylinder.

Inclination of the nozzle holder has, up to this time, resulted in another compromise which adversely affects the geometry and the performance of one or more of the nozzle orifices.

I have now invented a nozzle tip which, when used in conjunction with an inclined nozzle holder, provides the desired identical geometery for all the orifices.

The object of this invention is to provide a nozzle tip for direct fuel injection internal combustion engines such that the advantage of an inclined nozzle holder installation may be combined with the advantage of identical geometry of all the nozzle orifices, this combination not having been previously available.

Referring to the drawings:

FIG. 1 shows a partial section of a conventional injection nozzle assembly as installed at an angle to the axis of an engine cylinder; and

FIG. 2 shows a partial section of a nozzle assembly in accordance with this invention as installed at an angle to the axis of an engine cylinder.

Referring more particularly to the drawings:

With reference to FIG. 1, the portion of an engine cylinder head immediately surrounding a conventional injection nozzle is shown generally at 10. The axis 12 of the nozzle holder is shown at an angle {3 to the axis 11 of the cylinder bore. It will be seen that the external surface of nozzle tip 13 (hemispherical as shown) is a solid of revolution generated about the axis 14 of sac hole 15; it will also be seen that the axes of sac hole 15 and nozzle valve 16 are in line with nozzle holder axis 12 which is at angle ft to cylinder axis 11.

In order to achieve uniform wall thickness of nozzle tip 13 the external surface of 13 and the surface of the blind end of sac hole 15 usually take the form of con- 3 ,3Z6,19 l Patented June 20, 1967 centric hemispheres (though such other configurations as concentric cones are sometimes employed).

It will be evident that orifices 17, drilled radial to the hemispherical portion of tip 13, must be of equal length and that the intersections of orifices 17 with sac hole 15 and the external surface of nozzle tip 13 are plane circles; this is to say that all orifices 17 are of right circular cylindrical form, this being the best known configuration for the satisfactory formation and dispersion of the fuel spray.

In contemporary direct injection engines of the automotive type, there are usually four equally spaced orifices having their axes at an angle of 15 or 20 to a plane transverse to the cylinder axis, this angle being designated on in FIG. 1.

If the angle a is, for example, 15 and if the angle ,8 is 20, then at least one orifice 18 (of four equally spaced orifices) must penetrate nozzle tip 13 and sac hole 15 off the limits of this hemispherical portion. This is to say that at least one of the four orifices is longer than the others and that neither its intersection with the wall of sac hole 15 nor its intersection with the external surface of nozzle tip 13 will be a plane circle, therefore, one, at least, of the four orifices will have spray characteristics different from the others, which is undesirable.

FIG. 2 shows a nozzle assembly substantially in accordance with my US. Patent 3,118,611 but with a curved nozzle tip. The portion of an engine cylinder head immediately surrounding the nozzle assembly is shown generally at 20. The axis 22 of the nozzle holder is shown at an angle 5 to the axis 21 of the cylinder bore. The axis 24 of sac hole 25 is curved so that tangent 26 to curved axis 24 is parallel with axis 21. The axes of orifices 27 intersect curved axis 24 of sac hole 25 at a common point 28 and it is at this point that tangent 26 is tangent to curved axis 24. Hemispherical end 29 of nozzle tip 30 is a solid of revolution about tangent 26. The axes of orifices 27 make equal angles a with a plane transverse to axis 21, and all orifices 27 intersect the nozzle tip in its hemispherical end 29 whereby all orifices 27 are right circular cylinders of equal length.

Outwardly opening nozzle valve 31 is provided with retraction piston 32 whereby post-injection dribble, usually associated with a relatively long sac hole, is avoided.

The curved sac hole which characterizes a nozzle according to this invention is achieved by bending the nozzle tip subsequent to formation of its external surface and drilling of the sac hole.

From the foregoing, it will be seen that I have invented means and method for providing multiple orifices of identical geometery and desired spray angle in combination with a nozzle holder inclined at an angle to the axis of the engine cylinder.

I claim:

1. In a fuel injection nozzle for installation in an engine cylinder with the axis of the nozzle body inclined at an angle to the axis of the engine cylinder, a nozzle body having a duct for the passage of fuel, a nozzle tip member connected to said nozzle body and having a portion extending outwardly therefrom, said outwardly extending portion being provided with a sac hole for conducting fuel from said nozzle body to the nozzle orifice means, said outwardly extending portion of said nOZZle tip member having its axis so curved that a tangent to the extremity of said curved axis at its end remote from said nozzle body 3 4 is substantially parallel with the axis of said engine 3,118,611 1/1964 Berlyn 239-533 y 3,213,523 10/1965 Boehler 1 29-157 2. A fuel injection nozzle according to claim 1 wherein a reciprocable valve member is provided in said nozzle body for controlling the passage of fuel through said duct, 5 a retraction piston is operatively connected to said valve 3,216,093 11/1965 Tranel 29157 FOREIGN PATENTS member and spring means normally urges said valve mem- 553,048 2/1958 Canadaher to closed position, 130,763 8/ 1919 Great Britain. 3. A fuel injection nozzle according to claim 1 Where- 842,807 7/1960 Great Britain.

in the nozzle orifice means comprises a plurality of orifices 10 1 5 41 5 19 5 SwitZe1-1and whose axes intersect the axis of the sac hole at a common POint- M. I-IENSON WOOD, m, Primary Examiner.

References Cited UNITED STATES PATENTS ROBERT B. REEVES, Examiner. 3 074 52 1 19 Armstrong 239 533 15 R. S. STROBEL, Assistant Examiner.

3,080,123 3/1963 Ems 239601 

1. IN A FUEL INJECTION NOZZLE FOR INSTALLATION IN AN ENGINE CYLINDER WITH THE AXIS OF THE NOZZLE BODY INCLINED AT AN ANGLE TO THE AXIS OF THE ENGINE CYLINDER, A NOZZLE BODY HAVING A DUCT FOR THE PASSAGE OF FUEL, A NOZZLE TIP MEMBER CONNECTED TO SAID NOZZLE BODY AND HAVING A PORTION EXTENDING OUTWARDLY THEREFROM, SAID OUTWARDLY EXTENDING PORTION BEING PROVIDED WITH A SAC HOLE FOR CONDUCTING FUEL FROM SAID NOZZLE BODY TO THE NOZZLE ORIFICE MEANS, SAID OUTWARDLY EXTENDING PORTION OF SAID NOZZLE TIP MEMBER HAVING ITS AXIS SO CURVED THAT A TANGENT TO THE EXTREMITY OF SAID CURVED AXIS AT ITS END REMOTE FROM SAID NOZZLE BODY IS SUBSTANTIALLY PARALLEL WITH THE AXIS OF SAID ENGINE CYLINDER. 